Anatomy Chapter 3

Front 1

Plasma Membrane

Back 1

Separates the cell from its surrounding environment.

Front 2

Cytoplasm

Back 2

Thick gel-like substance inside of the cell composed of numerous organelles suspended in watery cytosol.

Front 3

Nucleus

Back 3

Large membranous structure near the center of the cell.

Front 4

Membranous Organelles

Back 4

Sacs and canals made of the same material as the plasma membrane.

Front 5

Fluid Mosaic Model

Back 5

Theory explaining how cell membranes are constructed.

Front 6

Cell Membranes

Back 6

Double layer of phospholipid molecules - Heads are hyrophilic, tails are hydrophobic. Most of the bilayer is hydrophobic.

Front 7

Transport Proteins

Back 7

Proteins embedded in the phospholipid bilayer that serve as passages for Na+ ions or glucose.

Front 8

Nonmembraneous Organelles

Back 8

Made up of microscopic filaments or other nonmembraneous materials.

Front 9

Rough Endoplasmic Reticulum

Back 9

Ribosomes synthesize proteins , which move toward the golgi apparatus and then eventually leave the cell.

Front 10

Smooth Endoplasmic Reticulum

Back 10

Synthesize certain lipids and carbohydrates and creates membranes for use throughout the cell.
*Removes and stores Ca++ from cells interior.

Front 11

Ribosomes

Back 11

*Each one is a nonmembranous structure made of two pieces, a large subunit and and a small subunit. Each unit is composed of rRNA.
*Free ribosomes make proteins for the cells domestic use.

Front 12

Golgi Apparatus

Back 12

Membranous organelle consisting of cisternae stacked on one another and located near the nucleus.
*Processes protein molecules from the E.R.
*Processed proteins leave the final cisternae in a vesicle; contents may then be excreted from the cell.

Front 13

Lysosomes

Back 13

The digestive system of the cell.
*Made of microscopic membranous sacs that have "pinched off" from the golgi apparatus.

Front 14

Proteasomes

Back 14

Hollow protein cylinders found throughout the cytoplasm.
*Breakdown abnormal/misfolded proteins and normal proteins no longer needed by the cell.

Front 15

Peroxisomes

Back 15

Small membranous sacs containing enzymes that detoxify harmful substances that enter the cells (often seen in kidney and liver cells)

Front 16

Mitochondria

Back 16

The power plant of the cell. Enzymes catalyze series of oxidation reactions that provide 95% of the cells energy.
*Each mitochondrion has a DNA molecule, allowing it to produce its own enzymes and replicate copies of itself.

Front 17

Nucleus

Back 17

Spherical body in center if the cell; enclosed by an envelope with many pores.

Front 18

Nucleus Structure

Back 18

Nuclear envelope: Composed of 2 membranes each with essentially the same molecular structure as the plasma membrane, surrounding nucleoplasm.
*Contains DNA which appear as the following...
- Chromatin threads or granules in non-divinding cells.
- Chromosomes in early stages of cell division

Front 19

Cytoskeleton

Back 19

The cells internal supportin framework made up of rigid, rodlike pieces that provide support and allow movement and mechanisms that can move the cell or its parts.

Front 20

Cell Fibers

Back 20

Intricately arranged fibers of varying lengths that form a three-dimensional, irregularly shaped network. Fibers support the ER, mitochondria, and free ribosomes.

Front 21

Types of Cell Fibers

Back 21

*Microfilaments - Cellular muscles that are made of thin, twisted strands of protein molecules that lie parallel to the long axis of the cell.
*Intermediate Filaments - Twisted protein strands slightly thicker than microfilaments; they form much of the supporting framework in many types of cells.
*Microtubules - Tiny hollow tubes that are the thickest of the cell fibers. They are made of protein subunits arranged in a spiral fashion. Their function is to move things around the cell.

Front 22

Centrosome

Back 22

An area of the cytoplasm near the nucleus that coordinates the building and breaking of microtubules in the cell.

Front 23

Cell Extentions

Back 23

Cytoskeleton forms projections that extend the plasma membrane outward to form tiny, fingerlike processes.

Front 24

Types of Cell Extention

Back 24

*Microvilli - Found in epithelial cells that line the intestines and other areas where absorption is important; they help to increase the surface area manyfold.
*Cilia & Flagella - Cell processes that have cylinders made of microtubules at their core; cilia are shorter and more numerous than flagella - flagella are found ONLY in human sperm cells.

Front 25

Desmosomes

Back 25

Fibers on the outer surface of each desmosome interlock with eachother; anchored internally by intermediate filaments of the cytoskeleton.

Front 26

Types of Desmosomes

Back 26

*Spot Desmosomes - Like "Spot Welds" at various points.
*Belt Desmosomes - Encircle the entire cell like a collar.
*Gap Junctions - Form channels that join the cytoplasm of two cells - fuse two plasma membranes into a single structure.
*Tight Junction - Molecules cannot permeate the cracks of tight junctions; occur in the linig of the intestines and other places where it is important to control what gets through the sheet of cells.